Machine tool

Abstract

A machine tool includes a linear movement axis for moving a main spindle, at least two linear movement axes for moving a table, and a rotation table including at least one rotation axis, the rotation table being placed on the table. A numerical controller performs machining by executing a machining program for tool center point control where the tool orientation is fixed to a certain axis or a certain surface, and by changing the tool orientation by controlling each axis of the machine tool based on set tool use range and tool orientation change waveform pattern.

What is claimed is: 
     
       1. A machine tool comprising:
 a linear movement axis for moving a main spindle; 
 at least two linear movement axes for moving a table; 
 a rotation table including at least one rotation movement axis, the rotation table being placed on the table; and 
 a numerical controller for controlling the main spindle, the linear movement axes, and the rotation movement axis according to a machining program in which tool orientation is fixed, and for machining a workpiece fixed to the rotation table, 
 wherein the numerical controller includes
 a tool shape information storage section for storing tool shape information to be used, 
 a reference machining orientation tool diameter storage section for storing a reference machining orientation tool diameter of a tool to be used in execution of the machining program in which tool orientation is fixed, 
 a tool orientation change waveform storage section for storing a tool orientation change waveform pattern and the number of repetitions for periodically changing a tool orientation of the tool to be used in execution of the machining program, 
 a machining direction vector storage section for storing a machining direction vector instructed by the machining program, 
 a movement axis instruction storage section for reading the machining program and storing movement axis instructions for the linear movement axes and the rotation movement axis, 
 a total machining height calculation section for calculating a total machining height for changing the tool orientation from the machining direction vector and the movement axis instruction, 
 a movement axis instruction value calculation section for calculating, by a tool center point control function, a movement axis instruction value for each of the linear movement axes and the rotation movement axis, which are movement axes, based on the movement axis instruction, 
 a movement axis instruction value addition amount calculation section for calculating an addition amount to each movement axis instruction value for changing the tool orientation, based on the tool shape information, the reference machining orientation tool diameter, the tool orientation change waveform, and the total machining height, 
 a movement axis instruction value adding section for adding the addition amount calculated by the movement axis instruction value addition amount calculation section to each movement axis instruction value calculated by the movement axis instruction value calculation section, and 
 a control section for performing operation according to each movement axis instruction value to which the addition amount is added by the movement axis instruction value adding section. 
 
 
     
     
       2. The machine tool according to  claim 1 , wherein the machining direction vector is an element for determining an axis direction of the tool orientation change waveform in the changing of the tool orientation. 
     
     
       3. The machine tool according to  claim 1 , wherein the total machining height is an element for determining a range of the tool orientation change waveform in the changing of the tool orientation.